But plaintiff attorney Don Holladay, who represents two Oklahoma lesbian couples, suggested an ironclad reason they sued Smith: a 10th Circuit panel of judges ordered them to sue the clerk in 2009.

The argument looms large because if the defense is correct, then the plaintiffs’ court odyssey that began in 2004 will have been in vain.

“If the court agrees on our issue, that will end the case,” Campbell said.

Thursday’s hearing in Denver was the second time in a week that the same panel of judges heard arguments on the issue of gay marriage. Utah’s case came April 10, but arguments in that case seemed to be more on point — whether gay marriage bans are unconstitutional or individual states have the right to define marriage.

Court watchers say it could take months for a decision in the cases, which are expected to eventually land before the U.S. Supreme Court.

“We’re ecstatic,” said Sharon Baldwin, standing alongside her partner of 17 years, Mary Bishop, after the hearing. “We think the hearing went well. We think justice is on our side.”

Her optimism came despite a long history of tough setbacks. Plaintiffs, who also include partners Susan Barton and Dr. Gay Phillips, first sued Oklahoma’s governor and attorney general the day after voters passed a constitutional amendment banning gay marriage Nov. 3, 2004.

But in 2009, the first panel of 10th Circuit judges to review the case ruled that they shouldn’t have named the governor and attorney general as defendants. So plaintiffs then sued Smith instead.

In January, U.S. District Judge Terence Kern struck down Oklahoma’s gay marriage ban, but in his ruling he pointed out that they should have sued the governor and attorney general.

Kirk Mitchell is a general assignment reporter at The Denver Post who focuses on criminal justice stories. He began working at the newspaper in 1998, after writing for newspapers in Mesa, Ariz., and Twin Falls, Idaho, and The Associated Press in Salt Lake City. Mitchell first started writing the Cold Case blog in Fall 2007, in part because Colorado has more than 1,400 unsolved homicides.